Some of my athletes have heard me using an elaborate "cue" lately. I've told some of them to think of the descending (eccentric) phase of the squat or the press as if they're simultaneously fueling and lowering a rocket onto the launch pad. At the moment the missile is on the pad, it launches. The "fuel" is the tension that accumulates in the muscles and other soft tissues. On the way down, you "load" the tightness, and at the instant you're on the launch pad (the bottom) you "explode."
So the cue is "load and explode." This crude analogy doesn't just speak to the importance of maintaining tightness (the fuel or "load") during the lift, especially during the eccentric phase. The launch pad is also part of the metaphor. If a rocket isn't aligned properly on the launch pad, the results are likely to be...unfortunate. The missile must be at exactly the correct place on the launch pad, correctly aligned, to fly properly. And this latter point underscores something I've been thinking about a lot: Barbell training is a precision activity. This is not necessarily true of exercise (although it may be, depending on the activity). Sweatin' to the Oldies, running on a treadmill, working up a sweat with machines, or step aerobics just aren't that terribly technique-dependent. But if a heavy squat isn't precisely placed on your back, if the bar path isn't precisely correct, if the bottom position isn't exactly where you want it to be, then the movement will be inefficient, or even result in a miss.
Large masses moving in the earth's gravitational field like to move in exactly straight lines (relativistic considerations notwithstanding). Not sorta straight lines, but exactly straight lines. Anatomical levers work best when joint and body segment angles are aligned so as to recognize this simple Newtonian fact, and to optimize their performance under loading. A press that gets even a little too far out front will miss. A deadlift on our toes will suck...or not go at all. Moving heavy weight with muscle and bone is an engineering problem that does not admit of any slop or corner-cutting. We're talking BMW here. Not Yugo. But the demand for precision goes beyond technique. Training heavy demands that we meet well-considered nutritional requirements, get appropriate sleep, and progress our program in a rational, careful manner that recognizes the biology of stress, recovery, and adaptation. All of these parameters are constantly and consistently monitored, evaluated, modified, and tailored precisely to our training situation and our individual attributes, becoming progressively individualized (and more precise) as we progress from novice to intermediate, to advanced intermediate, and beyond. We don't leave things to chance. We have a plan, and a record (a log, recorded in Wt x Reps x Sets format, thank you very much), in which all work product is documented for future analysis and ongoing refinement of the program. It is true that, in practice, we make some decisions on the fly, make changes when they seem to be indicated by the circumstances, and occasionally have to accommodate the vagaries of life. But the underlying nature of the enterprise remains the same: working to optimize the performance of the wonderful machines of brain, bone, blood, and muscle we call our bodies. In such an undertaking, we must leave as little to chance as possible, and our attention to detail must rival that of the engineer, the physiologist, the ballet dancer, the navigator. Strength training is a precision activity. It's something worth thinking about, and a valuable attitude to bring to your training lifestyle, on and off the platform.